The present invention was made to improve the operation and use of a hydraulically powered direct drive dual drum line and cable winch mounted on the deck of a mobile well tending rig, as shown in U.S. Pat. No. 4,432,532, February, 1984, Overholt. The invention enables an operator using the dual drum winch to selectively, precisely and safely raise and lower a "sandline" and a "tubing cable" elevated by a mast above a working well producing oil and gas (or water), for routine maintenance and service.
At present, the inventor has no knowledge of any prior art patents which could, alone or in combination, defeat novelty of the invention. It is assumed that prior art patents developed during examination of U.S. Pat. No. 4,432,532 will be considered during examination of this application.